A known example for a corresponding selection device is the rotational circular transporter, on which the different lamps are arranged and then turned to the corresponding position for the emission of the light radiation in the direction of the atomizing device.
Furthermore, in practice the usual arrangement is known, in which at least one optical element is moved, in order to select a particular lamp of the light source. Such an arrangement has the advantage that automatic fine-tuning can be achieved without moving the lamp itself. For this reason, selection is constructively easier and also much quicker. With such a structure, several measurements can be carried out successively during the atomizing of specific tests with different lamps.
The movement of the optical selector in the above-mentioned device, occurs in two dimensions for the lamp selection and for accuracy. Another disadvantage of this device is that it is relatively large and the device controlling two-dimensional movement of the optical element is relatively complex.